The variable is the plan benefit package (PBP) number for the beneficiary’s managed care plan. CMS assigns an identifier to each PBP within a contract that a plan sponsor has with CMS.
You need to know both the contract number (variable called CNTRCT_NUM) and plan benefit package number (plan ID) in order to identify the specific plan in which a beneficiary was enrolled. CNTRCT_PBP_NUM is not submitted by the MAO on an encounter data record; the MAO only submits the contract ID. Instead the plan ID is assigned by CMS based on the beneficiary’s enrollment data for the claim dates of service. CMS enrollment data is obtained from the source CMS Common Medicare Environment (CME) data
Source: CMS Encounter Data System (EDS)